Hitachi 1TB Deskstar E7K1000 Saturn.E

The Hitachi 1TB Deskstar E7K1000 Saturn.E (“E7K1000”) hard drive is a high-performance enterprise class drive suitable for RAID. See also results from the older and non-enterprise Hitachi DeskStar 7K1000.

The Saturn E7K1000 also makes a superb choice for external eSATA, even for the MacBook Pro, where it is a top performer.

Get the Saturn E7K1000 at site sponsor OWC Computing. OWC is one of the few vendors which have a drive replacement guarantee, well worth the piece of mind and convenience. Please give OWC your business by clicking any of the ads or links in this Guide.

Low power consumption

The Saturn is one of a new breed of lower power consumption drives, drawing only 5.2 watts at idle, compared with 8-12 watts for most drives into early 2009. That low power consumption translates to savings on operating costs, lower stress on the machine, and quieter operation. A Mac Pro with 4 hard drives in its bays could save 12-28 watts by using the Saturn compared with other drives.

The new Western Digital Green 2GB specifies a 4 watt idle, so this is apparently the start of a trend in the disk drive industry.

The graph below shows performance across the drive as it was filled to capacity with 1000 equal-sized files, written 32MB at a time. See Why you need more space than you need to understand the performance gradient across the drive.

Variance of file write times (ms)Read speeds were effectively identical

The graph below shows performance across the volume as it was filled to capacity with 1000 equal-sized files, written 32MB at a time (this test takes over 6 hours to read and write the 3.6TB volume). See Why you need more space than you need to understand the performance gradient across the drive.

This is a 4-drive stripe using the Sonnet Tempo E4P with 4 eSATA cables to a FirmTek SeriTek/2eEN4. We see near-perfect scalability over a single drive, and outstanding consistency (minimal variance) in speed at any position on the drives. See similar results from the Western Digital RE-3.

The graph makes it clear why you’d want a Photoshop scratch volume (partition) to be on the fast side of the drive—carve off 64GB or whatever you need there to get the ~430MB/sec for maximum performance.

Variance of file write/read times (ms)Red line is write, green line is read

Speed across the drive, MacBook Pro 2.93GHz, dual drive RAID stripe

MacBook Pro users looking for maximum performance (especially with Photoshop) can use the ExpressCard slot to attach an eSATA enclosure containing two or more hard drives. For highest performance, the Sonnet Tempo SATA Pro is recommended as of March 2009.

Read speed is slightly better than write speed on the first 1/3 of the drive. Also, the flat performance curve for the first 1/3 of the volume indicates that maximum speed is being throttled by the limitations of the PCI ExpressCard itself (not the hard drives); otherwise speeds would reach the ~220MB/sec range.

Variance of file write times (ms)Red line is write, green line is read

Get your own copy of DiskTester for testing your drives, RAID, network, etc.

Sequential sustained transfer

Performance with varying transfer sizes is simply outstanding, this is one of the most consistent drives yet tested in this regard. Many drives fail to perform well at smaller chunk sizes. Outstanding!